The Kurdish political bloc has stopped all participation in Iraq's national government over prime minister Nouri al-Maliki's comments that Kurds were hosting Sunni rebels in Erbil.

Iraq's foreign minister, Hoshiyar Zebari, said on Friday that Kurdish politicians would stop running their ministries, a day after they had announced a boycott of cabinet meetings.

The ministries affected include Zebari's foreign ministry, the trade ministry, the ministry of migration, the health ministry and the deputy premiership, the Reuters news agency reported.

Kurdish MPs would continue to attend the parliament, elected on April 30, Zebari said, adding the country risked falling apart if an inclusive government was not formed.

"The country is now divided literally into three states; Kurdish; a black state [the area controlled by the Islamic State group] and Baghdad."

Despite the foreign minister's comments, the Iraqi state television said reports that the Kurdish bloc had suspended participation in the government were not "fully accurate".

It quoted Kifa Mahmoud Karim, an adviser to the Kurdish regional government's president, as saying the ministers consider themselves to be "on leave".

Karim said the politicians would go back to Baghdad once the parliament agreed on nominations for the presidency and speaker of the house.

Also on Friday, Kurdish peshmerga soldiers took control of two oilfields near Kirkuk on Friday, expelling Arab workers and replacing them with Kurdish personnel, the oil ministry said.

The Kurdish forces had moved in to Kirkuk in June shortly after Iraqi government forces fled in face of an offensive by Islamic State group fighters.

Sistani condemnation

In a separate development, Iraq's most revered Shia religious leader, Ali al-Sistani, called on politicians to "close ranks" and to stop what he called their "radical discourse".

The Iraqi prime minister's accusation that the Kurdish regional government was harbouring fighters from the Islamic State group sparked a war of words between him and the Kurdish regional president, Massoud Barzani.

Iraq's political fractures were exposed after a rebellion led by Islamic State group fighters seized large parts of the country.

Maliki has accused the Kurds of exploiting the crisis to push for statehood.